ML19095A752

Submit Abnormal Occurrence Report No. AO-S1-75-12 Re No. 3 Emergency Diesel Generator Was Running & Feeding 2J Bus When It Failed

ML19095A752
Person / Time
Site:	Surry
Issue date:	05/09/1975
From:	Stallings C Virginia Electric & Power Co (VEPCO)
To:	Moseley N NRC/RGN-II
References
Serial No. 524 LER 1975-012-00
Download: ML19095A752 (3)

Text

.. "*"'j.

VIRGINIA ELECTRIC .A.ND PowER COMPANY RICHMOND, VIRGINIA 23261 May 9, 1975 Mr. Norman C. Moseley, Director Serial No. 524 Office of Inspection and Enforcement PO&M/JTB:clw United States Nuclear Regulatory Commission Region II - Suite 818 Docket Nos. 50-280 230 Peachtree Street, Northwest License Nos. DPR-32 Atlanta, Georgia 30303

Dear Mr. Moseley:

Pursuant to Surry Power Station Technical Specification 6.6.B.l, the Virginia Electric and Power Company hereby submits forty (40) copies of Abnormal Occurrence Report No. Ao...:sl-75-12.

The substance of this report has been reviewed by the Station Nuclear Safety and Operating Committee and will be placed on the agenda for the next meeting of the System Nuclear Safety and Operating Committee.

Very truly yours, t;_m.J~~~

C. M. Stallings Vice President-Power Supply and Production Operations Enclosures 40 copies of AO-Sl-75-12 cc: Mr. K. R. Goller

LICENSEE EVENT REPORT Ao-s 1_ 75 _ 12

....

• CONTROL BLOCK: I* I I I I I 'EASE PRINT ALL REQUIRED INFORMATION) 1 6 LICENSEE NAME B!egulatory Docket 1

LICENSE NUMBER -

fj~NSE

- - - * ----*.i;.,.-:,~T-YPE 0

EVENT TYPE

@El Iv IA Isl Pl sl 11 Io Io 1-1 oI oI O I O 1° 1-1 °.~ I 4 11 I 1 ! 1 I oI I OI1 I 7 8 9 14 15 25 26 30 31 32 REPORT REPORT CATEGORY TYPE SOURCE DOCKET NUMBER EVENT DATE REPORT DATE

@IT] CON'T 7 8 IP I O j 57 58 w59

~

60 101s 61 101-1° 1 2 18 1°1 68 IOl4l3IOl7!SI 69 74 lo !s Io 17 I 7 I s I 75 80 EVENT DESCRIPTION

@lg] I Number 3 emergency diesel generator was running and feeding the "2j" bus when it I 7 8 9 80 loj3j I failed. Several attempts were made to restart the engine but each time the engine I 7 8 9 80

@El j would run for several seconds and then stop. AO-Sl-75-12 I 7 8 9 80

~ .___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___J 7 8 9 80

&@I 7 8 9 PRIME 80 SYSTEM CAUSE COMPONENT COMPONENT CODE CODE COMPONENT. CODE SUPPLIER MANUFACTURER 7

@El 8 9 I E!E I 10 w 11 IEIN!GlrlN!E]

12 17

~

43 I EI 1 I 41 71 44 47 CAUSE DESCRIPTION

~ I Electro-Motive Div. of GM Model 645E4 diesel engine. Planetary and spline shaft gears!

7 8 9 80

~ l of the mechanical drive of the turbo-blower were partially stripped of teeth. Th~ . _.,

7 8 9 E1§l I mechanical drive is designed to run the turbo-blower only long enough for the. (cont '.d5j 7 8 9 80 FACILITY METHOD OF STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION EID8 7

w 9

FORM OF 10 11 CONTENT IO 1*0 12I .______;'-------

13 N/A 44 ' ~45 I N/A 46 80 ACTIVITY rn w RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE 7 8 g

~

10 I

11 N/A 44 45 N/A 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION

~ lo 10 I 01 ~ N/A 7 8 9 11 12 13 80 PERS.ONNEL INJURIES NUMBER DESCRIPTION 7

rn 8 9 1° I O I O11I 12 N/A 80 OFFSITE CONSEQUENCES Ee] N/A 7 8 9 80 LOSS OR DAMAGE TO FACILIJY TYPE DESCRIPTION

~ W N/A 7 8 9 10 80 PUBLICITY

[ITf] N/A 7 8 9 80 ADDITIONAL FACTORS

~ l The failure of No. 3 emergency diesel generator led to the trip of Unit No. 1 reactor I 7 8 9 80 EJfil I through the following sequence of events. Breaker 25J8 was being tested and (cont'd) 7 8 9 80 NAME: E. M. Sweeney, Jr. PHONE: (804) 357-3184 GPO 8 81*66 7

i .

... . e CAUSE DESCRIPTION (cont'd) engine speed and exhaust temperature to cause the turbine drive of the turbo-blower to overrun the mechanical drive and disengage the clutch. The turbo-blower is then run by the exhaust gases being fed into the turbine drive. In this case the engine speed and loading were not sufficient to disengage the mechanical drive. Corrective action is to ensure the engine speed and loading are sufficient to disengage the mechanical drive to the turbo-blower. The above failure could have rendered this diesel incapable of performing its intended function.

ADDITIONAL FACTORS (cont'd)

No 3 diesel was suppling th~ 2J bus; therefore,* failure of the diesel chused breaker 25J8 to trip which resulted in the tripping of breaker 15Fl (Double Protection Circuitry) and the loss of bus lH on Unit No. l'. One of the inverters supplying the 110 volt vital buses was out of service which, with the loss of the lH bus, dropped another 110 volt vital bus and tripped Unit No. 1 reactor.